Sander



Feb. 17, `1959 A. J. LEVINE SANDER Filed March 18, 1957 United StatesPatent O 2,873,561 SANDER Aaron J. Levine, Chicago, Ill.

Application March 18, 1957, Serial No. 646,599

8 Claims. (Cl. 51-170) This invention relates to power driven sandingdevices adapted to be mounted upon and driven by a portable electricdrill, and has for its principal object the provision of a new andimproved device of this kind.

It is a main object of the invention to provide a sanding device whichcan be readily atatched to and removed from a portable electric drillfrom the shaft of which the usual drill chuck has been'removed.

Another object of the invention is to provide a power sanding device formounting on a portable electric drill, which device is of light weightand balanced properly for ease of handling during operation.

Another object of the invention is to provide a sanding attachment for aportable electric drill, which attachment can be manufacturedeconomically without sacricing quality and can remain in properoperating condition with a minimum of maintenance.

Further objects of the invention not specifically mentioned here will beapparent from the detailed description and claims which follow,reference being had to the accompanying drawings in which a preferredembodiment of the invention Vis shown by way of example and in which:

Fig. 1 is a side elevational view of the sanding device attached to aportable electric drill;

Fig. 2 is a cross sectional view taken substantially along the line 2-2of Fig. l, looking in the direction of the arrows;

Fig. 3 is an end view of the device, partly in section, along the line3--3 of Fig. 1, looking in the direction of the arrows; and

Fig. 4 is a fragmentary cross sectional view along the line 4 4 of Fig.2, looking in the direction of the ar rows and drawn to an enlargedscale.

Handymen and hobbyists have frequent use for a power sanding device, andsince most such men are equipped with a portable electric drill it isadvantageous to provide a sanding device which can be readily attachedto and detached from an electric drill from which the usual chuck hasbeen removed, thereby to form a power driven sanding tool that iseconomical to purchase and maintain. The present invention providesysuch a sanding device and employs a bracket such as that shown in mycopending application Serial No. 640,# 109, led February 14, 1957, whichforms the base of the sanding tool and permits its ready attachment toand detachment from the casing of a portable electric drill.

In one instance, a quarter inch electric drill, available on the openmarket, has a free running speed of 2000 R. P. M.; and when the sandingattachment of the present invention is mounted upon such a drill, thesanding plate of the device is oscillated at a speed approach-ing 2000oscillations per minute. Obviously, with an abrasive element of propercoarseness mounted upon the sanding device, finish sanding of a piece ofwork The invention will be best understood from the draw;V

ings in which, in Fig. l, the device is shown attached to a portableelectric drill of known make. The sand ing attachment comprises abracket 1 which may conveniently be of the type shown in the abovementioned application, which bracket is secured to the casing 2 of thedrill by suitable means such as screws 3. Depending below the drillcasing encompassing portion of the bracket 1 are feet 4 and 5 which haveflat bottoms 6 disposed in a plane that is parallel to a horizontalplane through the axis of the drill shaft. The outer edges 7 of the feet4 and 5 are planar and disposed in parallel vertical planes disposedequidistantly on the two sides of the axis of the drill shaft.

The sanding device includes a base plate 8 out of the upper surface ofwhich ribs 9 are projected, these ribs having straight inner sides whichengage the planar edges 7 `of the feet when the plate is mounted uponthe bracket 1.

In order to mount the plate upon the bracket land to provide foroscillatory movement thereof in the direction of the axis of the drillshaft, feet 4 and 5 are each provided with upwardly facing ledges 10which are the bottoms of arcuate indentations 11 formed in the feet.Ribs 9 are provided with circular bosses 12 that extend above the ribsat the longitudinal centers thereof, which bosses and ribs are threadedto receive screws 13 by which the base plate 8 is secured upon thebracket.

As will be seen best in Fig. 4, when the `head or screw 13 is tighteneddown upon the upper surface of the boss 12, the portion of the head ofthe screw which overhangs the upwardly facing ledge 10 of the foot ofthe bracket is spaced away from that ledge, thereby to insure thattightening of the screws will not clamp the feet 4 and 5 onto the baseplate 8 so as to prohibit movement therebetween.

Fixed upon the drill shaft is a driving wheel 15 which is inclined withrespect to the axis of the shaft, so that as the shaft and wheel arerotated the lowermost periphery of the wheel moves back and forth in adirection parallel to the axis of the shaft.

Fixed upon the base plate 8 by suitable means, such as screws 16, arelow friction bearings, either ball bearings or roller bearings, theouter rotatable cones 17 of which are disposed on opposite` sides of therim of drive wheel 15 and in engagement therewith. Thus rotation of theshaft moves the base plate in oscillatory motion with respect to thebracket 1, this movement extending for a distance depending upon thedegree of angularity between the disk-like portion of the driving wheel15 and the axis of the shaft. In one instance, 4the total movement ofthe plate with respect to the feet is approximately one-quarter of aninch.

Mounted upon the bracket 1 is a guard 20 which overhangs the drive wheel15, partly encompassing the same, thereby to protect the wheel andoperator of the device during operations of the device. The guard 20 issecured to the bracket by suitable means such as screws 21 and may becomposed of metal or plastic as desired.

Upstanding from the top of the bracket 1 is a boss 22 containing acavity into which the bottom of a suitable handle 23 is projected, thehandle being secured to the bracket by a screw 24 that is threaded intoa tapped hole at the bottom of the cavity.

Mounted upon the lower face of the base plate 8 is a resilient pad 25which preferably is composed of either synthetic or natural rubber,which pad serves to cushion the abrasive material.

8 'att'h' endsof the ribs `9 therein are locking means 26 by which ends27 of a sheet of abrasive material that is folded over onto the top ofthe base plate 8 are clamped to the base plate. The particular forni ofclamping means 26 is not of the essence of the present invention, theclamp shown by way of example beingof the type shown in the ScacePatents 2,683,336 and 2,683,337. It is sulicient to note here that theclamping bar 26 is pivoted bypintles 2S in journals at the ends of theribs 9, and that the 'operating handle 29 thereof may be grasped andswung outwardly into dotted position shown in Fig. 2, to permit raisingthe ciampiiig bar off of the upper surface of the base plate 3, therebyto permit registering lthe end 27 of the abrasive material with thatplate. The arm 29 is then raised to move the clamping portion 26 intoengagement with the end 27 and the arm 29 then swung inwardly past aboss Sti at the edge of the base plate to secure the abrasive materialon the plate.

Sanding'devices of this type will most generally employ sandpaper havingfairly line grit; however, if desired, emery paper or eni'ery cloth maybe used as an abrasive with 'the device.

I. The bracket 1 and base plate S are preferably formed by casting froma metal alloy which is self-lubricating, with the result that no otherlubrication is needed between the feet of the bracket and ribs and baseplate against which these feet arerengaged. The device is of simpleconstruction andV may be manufactured at low cost without sacr'icingquality and is capable of giving satisfactory performance for thepurposes intended, over a long period of time without maintenance.

While I have chosen to illustrate my invention by showing anddescribingT a preferred embodiment of it, I have done so by way ofexample only, as there are many modifications and adaptations which canbe made by one skilled in the art within the teachings of the invention.

Having thus complied with the statutes and shown and described 'apreferred embodiment of my invention, what I` consider new and desire tohave protected by Letters Patent is pointed out in the appended claims.

What I claim is:

1. A power sander for attachment tothe motor casing of a portableelectric drill, comprising a bracket detachably secured to the casing atthe shaft end thereof and having a perforation through which the shaftprojects; a driving wheel fixed upon the shaft and inclined with respectto the axis of the shaft; feet upon said bracket; a base plate; ribsupstanding from said base plate and engaging said feet to 'position theplate with respect to the bracket in a direction at right angles to theaxis of the shaft; means securing said base plate upon the bracket, saidmeans permitting limited movements of the plate with respect to thebracket in directions parallel to the axis of the shaft; means forestablishing a driving connection between said driving wheel and baseplate; an abrasive member upon the base plate; and means for 'securingsaid abrasive member upon said base plate.

2. A device as specified 'in claim 1, in which the feet on the bracketterminates in planar bottoms that lie in a plane that is parallel to ahorizontal plane through the axis of the shaft and have planar outeredges positioned in planes that are parallel to and equidistant from tthat axis and in which ythe ribs on the baseplate'engage said outeredges and have sliding t with respect thereto.

3. A device as specified in claim 1, in which the means for securing thebase plate to the bracket includes an upwardly facing ledge formed ineach foot adjacent the outer edge thereof, screws threaded dinto thebase plate having heads which overlie said ledges and bosses on the ribsagainst which the `screw heads are drawn tight with clearance remainingbetween th ledges Vand screw heads. y

4. A device as specified in claim l', in which the driving connectionbetween the wheel and base plate includes a pair of low frictionbearings xed upon the base plate on opposite sides of the wheel andengaging the opposite faces of the wheel at the rim thereof,

Y the wheel engagingportions of which bearings are rotatable on theplate. y

`5. A device as specified in claim 1, inV which` a pad of resiiientmaterial is secured to the face of the base plate away from the bracketto cushion the abrasive 7. A device as specified iii-claim l, in which ahandlel projects above the bracket at the center thereof and in which aguard fixed upon the bracket partially encases the driving wheel toprotect the same..

8. A device as specified iiirclaim l, in which the bracket and baseplate are cast from metal which forms self-lubricating joints betweenthe bracket and plate.

References Cited in the tile of this patent l UNITED srAras PATENTS2,639,620 Bamfcrd A May 26, i953 2,743,557 `Larson May l, 1956 2,755,673Dixon July 24, 1956

